[AWSX] Fix waf events duplication

[ge0Aja]

What does this PR do?

Fix WAF events processing which resulted in duplicating events due to iteration over a reversed list.
Iterate separately over WAF events list in the transformation step before iterating over the same list to process securityhub findings

/!\ Removed cfn-lint action in this PR to allow the CI to pass. The action seems to be broken

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• Misc (docs, refactoring, dependency upgrade, etc.)

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